Report

PH 211 Winter 2014 • • • • • • New course offering (also PH212 in Spring) Lab room Weniger 204 Syllabus has rules of the course Syllabus has daily schedule, midterms, labs Web-site has lab material Web-site: www.physics.oregonstate.edu/~jansenh/COU RSES/ph211 Registering your clicker: • BEFORE SUNDAY January 12th, register your clicker on BLACKBOARD using your clicker ID number on the back of the device (a 6 digit alphanumeric ID) • (We will test clickers Wed and Fri – but no points will be given until week 2) • MasteringPhysics code: MPJANSEN95607 - INPUT YOUR STUDENT ID – NO SPACES!!! • Lab Excuses: If you have taken 211 within the past 2 years and received a D- or better (and completed all of the labs), you can ask to be excused from the lab (you do need to remain registered): Email me your name, ID#, when you took lab, and your grade and I will confirm the lab excuse. for • LAB STARTS Thursday, RECITATION STARTS WEEK 2 • 1st hmwk is Chpt 3 – math review, ONLINE ONLY, due Monday at 2 before midnight– IS POSTED Labs Go to http://www.physics.oregonstate.edu/~jansenh/ COURSES/ph211/LABS/index.html Read Instructions in section A ahead of time. Lab 1 instructions will be on the lab computers. Google moderator Try a new tool (need google login): Which topic would you like to discuss in class on Friday? https://www.google.com/moderator/#16/e=20f 7a8 Do your voting question points depend on whether or not your answer is ‘correct’? CHANNEL 42 1. Yes 2. No Do your voting question points depend on whether or not your answer is ‘correct’? CHANNEL 42 1. Yes 2. No 71% o N Ye s 29% Where can you go for help? 1. 2. 3. 4. Weniger help room, 12-6 MTWRF Library help room, 6-10, SMTWR Professor office hours Discussion board (blackboard) What is a vector? • Set of instructions in the form move two chairs to the left • Anything with a length and direction • A picture like • An ordered set (L,dir) with L ≥ 0 • A formal mathematical concept, defined by addition, multiplication by scalar, zero, and inversion • All of the above Which figure most accurately represents the addition of vectors A and B? A 1. 2. 3. 4. Figure One Figure Two Figure Three Figure Four B A+B A+B Figure 1 Figure 2 A+B Figure 3 A+B Figure 4 Which figure most accurately represents the addition of vectors A and B? Figure 1 Figure 2 Figure 3 Figure 4 A B A+B A+B Figure 1 Figure 2 97% A+B ur e Fig ur e Fig 4 1% 3 1% 2 ur e Fig ur e 1 2% Fig A. B. C. D. Figure 3 A+B Figure 4 In order to agree on statements about vectors we need to agree on how we measure length and direction! Unit of length: meter Vectors and components = + Vectors and components = + = + Note that can point in the plus or minus î direction. We include the sign in the number Vectors and components = + = + Book always writes (length, direction) Common notation ( , ) An old clock The minute hand of a clock is 17.5 cm long. What is the vector connecting the tip of the minute hand at 8:00 am and 8:20 pm? What is the vector connecting the tip of the minute hand at 8:00 am and 11:00 pm? What is the sum of these four vectors? Which of the following mathematical statements is correct? 1. 2. 3. 4. Ctan(Θ) = A Ccos(φ) = A Csin(Θ) = B Csin(Θ) = A C A Θ B Φ Which of the following mathematical statements is correct? A. C tan(Θ) = A B. C cos(φ) = A C. C sin(Θ) = B D. C sin(Θ) = A C A Θ B Φ Quantitative addition/subtraction • Writing the vector in terms of its components using trig functions • Writing the length of a vector given its components • Writing the vector using unit vector notation • Writing vector sums using components • Write the vector (A-B) using at least 3 different mathematical representations Example problem 3.40 The treasure map in the figure gives the following directions to the buried treasure: "Start at the old oak tree, walk due north for 500 paces, then due east for 100 paces. Dig." But when you try that path you find an angry dragon by the tree. To avoid the dragon, you set off along the yellow brick road at an angle 60o east of north. After walking 300 paces you see an opening through the woods. Which direction should you go and how far in order to reach the treasure? Finding angle between vectors Vector A: (3,4) and Vector B: (2,8) Find the angle for each individual vector, and find the angle between the vectors Finding angle between vectors Vector A: (3,4) and Vector B: (2,8) Dot product: ∙ = + + Dot product: ∙ = cos()